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See detailOccurrence and significance of minute palynomorphs of marine and non - marine origin in the Middle Ordovician from Saudi Arabia
Le Hérissé, A.; Guidat, C.; Not, F. et al

Conference (2016, October 27)

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See detailSilurian palynomorphs from the Precordillera basin, western Argentina: biostratigraphy and diversity trends
Garcia Muro, V.J.; Rubinstein, C.V.; Steemans, Philippe ULg

Poster (2016, October 27)

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See detailLes 10 ans d’Envol à l’école Saint-Pierre : La musique et le conte au centre des apprentissages et du vivre ensemble dans les classes
Gavray, Claire ULg

Conference (2016, October 27)

historique du projet, évaluation des apports et perspectives

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See detailPlant functional trait diversity in wildflower strips: the key to promote pollinators in agricultural landscapes?
Uyttenbroeck, Roel ULg; Piqueray, Julien; Monty, Arnaud ULg

Conference (2016, October 27)

Creating wildflower strips is often suggested as a tool to support pollinator diversity in agricultural landscapes and to promote crop pollination service. The choice of the plant species to sow in flower ... [more ▼]

Creating wildflower strips is often suggested as a tool to support pollinator diversity in agricultural landscapes and to promote crop pollination service. The choice of the plant species to sow in flower strips can influence the effectivity of the strips in supporting pollinators. While it has already been shown that increasing plant species diversity is beneficial for ecosystem services, it is often suggested that plant functional traits and functional trait diversity are the key for this relationship. We created a replicated field experiment with different levels of plant functional diversity in wildflower strips in Belgium to test the effect on the flower-visiting pollinator community. We sampled plant-pollinator interaction networks during 2 years and assessed how the plant functional diversity affected the network structure. Plant functional diversity did not have a clear effect on visiting pollinator species richness, however a different interaction pattern was observed with different functional diversity level. Pollinators in wildflower strips with higher functional diversity had less overlap in their ecological niche, while network stability and robustness for secondary extinctions were not affected. We discuss implications for wildflower strip design. [less ▲]

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See detailNew features in SAFIR® 2016 - SWS 2016
Franssen, Jean-Marc ULg; Gernay, Thomas ULg

Scientific conference (2016, October 27)

Presentation of the new capabilities and developments in the version 2016 of SAFIR, a non linear software dedicated to the analysis of the behaviour of structures in fire.

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See detailL'Union européenne ou la désunion des valeurs
Bouhon, Frédéric ULg; Wildemeersch, Jonathan ULg

Scientific conference (2016, October 27)

Cette intervention visait à introduire l'exposé des ministres hongrois Laszlo Trocsanyi et polonais Aleksander Stepkowski. Les auteurs adressent une série de questions en lien avec les évolutions ... [more ▼]

Cette intervention visait à introduire l'exposé des ministres hongrois Laszlo Trocsanyi et polonais Aleksander Stepkowski. Les auteurs adressent une série de questions en lien avec les évolutions politiques et juridiques que connaissent la Hongrie et la Pologne, tant sur le plan interne (réformes électorales, réformes des juridictions constitutionnelles, mises en cause de certaines droits fondamentaux) que dans leurs relations avec l'Union européenne. [less ▲]

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See detailQuelques réflexions à propos du régime de (dé)fiscalisation des revenus des PME dans le système fiscal belge
Bourgeois, Marc ULg

in Aydogdu, Roman (Ed.) Les petites et moyennes entreprises dans le droit des affaires (2016, October 27)

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See detailDéfi climatique: l'état et le marché
Gautier, Axel ULg

Conference given outside the academic context (2016)

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See detailEcoNum, a research unit devoted to marine environment monitoring
Richir, Jonathan ULg; Batigny, Antoine; Georges, Nadège et al

Conference (2016, October 27)

The monitoring of coastal environments remains a research domain of great interest and concern. Coastal ecosystems are threatened by natural and human-induced stressors and are, as transitional ... [more ▼]

The monitoring of coastal environments remains a research domain of great interest and concern. Coastal ecosystems are threatened by natural and human-induced stressors and are, as transitional environments, particularly sensitive to disturbances. EcoNum first research thematic revolves around hermatypic corals, calcifying organisms, and their adaptation potentials to environmental changes including by using original and patented chemostats. The studied organisms are grown and maintained in artificial mesocosms that simulate environmental conditions of a natural system. This infrastructure allows to perform long-term experiments, giving time to organisms to adapt to the tested conditions (e.g., increased temperature or lowered pH). Longer-term studies have demonstrated that many organisms are more resistant to environmental stressors than previously observed on the short-term. EcoNum also studies coastal plankton abundance and diversity. Plankton is particularly sensitive to physicochemical changes of water bodies. The classification and the enumeration of planktonic organisms require specialized tools in order to analyse time series of multiple samples. EcoNum has developed a software for the semi-automatic classification of planktonic organisms called Zoo/PhytoImage. This software has been used to study a 10-year time series of coastal Mediterranean zooplankton samples. The concomitant analysis of environmental parameters registered at high frequency with specific statistical tools such as the R package pastecs allows to understand the processes governing the changes observed in plankton assemblages. The use and the development of statistical tools in R (e.g., Zoo/Phytoimage, pastecs) is a priority of EcoNum to favour open access knowledge and reproductive sciences. EcoNum research topics also focus on coastal ecotoxicology. Chemicals, including trace elements, remain contaminants of concern, mainly in coastal environments that are the final sink of inland pollution sources. The chemical integrity of coastal ecosystems thus has to be accurately monitored. The partitioning of chemicals between their dissolved, particulate and sedimentary phases does not provide information on their bioavailability. EcoNum thus monitors coastal waters using bioindicator species such as seagrasses, mussels or sand worms. A global map of the contamination of the Mediterranean by trace elements has been drawn using seagrasses has bioindicator species. EcoNum also studies trace element ecology and toxicology. For instance, it has demonstrated the toxicity of copper on the coral Seriatopora hystrix and it's symbiont's photosynthetic processes, or its bioaccumulation and basipetal translocation towards rhizomes in the seagrass Posidonia oceanica as reserve nutrient for subsequent leaf growth. Finally, coastal vegetated systems are potential carbon thinks (or sources) in the global carbon cycle. Therefore, EcoNum studies the primary productivity of seagrass meadows, from the individual to the community, with measuring techniques as diverse as PAM-fluorometry or biomass production determination. To conclude, EcoNum is a research unit devoted to marine environment monitoring. It develops research thematics on major coastal communities such as coral reefs, seagrass beds or plankton assemblages and studies their natural dynamics and the effects of stressors on their global functioning. [less ▲]

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See detailBollywood et les limites du soft power indien
Vlassis, Antonios ULg

in Telos (electronic journal) (2016)

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See detailCase report: Ovarian fibroma in a mare – Hormonal considerations
Ponthier, Jérôme ULg; Salciccia, Alexandra ULg; Parrilla Hernandez, Sonia ULg et al

in Reproduction in Domestic Animals (2016, October 27), 51(supplement 2), 132

This report shows that, as in humans, AMH as well as steroids productions are low in case of ovarian fibroma, thus preserving normal cyclicity.

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See detail6ème Cours de Mécanique Analytique II (2016-17), Bac3 phys, Master 1 Sc. Sp.
Surdej, Jean ULg

Learning material (2016)

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See detailLa vaisselle du Piano della Civita / Artena (Italie) : le témoignage du verre
Dienst, Simon ULg

Scientific conference (2016, October 27)

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See detailThe dynamics of market, credit and liquidity risk in the US corporate bond market
Heck, Stéphanie ULg

Doctoral thesis (2016)

Market, credit and liquidity constitute important risk factors in financial markets. Investors looking for optimal combinations of risk and return have to monitor their portfolios with regard to each of ... [more ▼]

Market, credit and liquidity constitute important risk factors in financial markets. Investors looking for optimal combinations of risk and return have to monitor their portfolios with regard to each of those factors. This work brings answers to some of the challenges presented by these three risk factors in the US corporate bond market. Market risk is the earliest and most widely acknowledged risk factor, affecting all financial securities. The risk that the issuer of the bond might go bankrupt introduces credit risk for corporate bonds. Finally, these securities are also characterized by a low trading frequency. Liquidity in this market has been severely affected by the recent global financial crisis as well as by the regulatory changes that followed the crisis. The first part of this dissertation studies the return premium investors require in compensation for undertaking credit risk. It is shown that distributional characteristics of individual assets and in particular the contribution of an asset’s return to the market portfolio’s skewness and kurtosis are important determinants of these premiums. The second part explores commonality in individual bond liquidity levels. It is shown that the pricing of liquidity in yield spreads is essentially due to this commonality. The final part of this dissertation designs a corporate bond market index based on the repeat-sales technique. The index adequately captures aggregate market dynamics and contributes to the explanation of the cross-section of individual corporate bond returns. [less ▲]

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See detailBounding surface plasticity model for natural clays
Ahayan, Sanae ULg; Yin, Zhen-Yu; Kotronis, Panagiotis et al

Conference (2016, October 26)

Natural soft clay exhibits a considerable degree of anisotropy as a result of its past sedimentation and consolidation history. It also tends to have significant inter-particle bonding, which affects its ... [more ▼]

Natural soft clay exhibits a considerable degree of anisotropy as a result of its past sedimentation and consolidation history. It also tends to have significant inter-particle bonding, which affects its mechanical behavior. The natural structure of in-situ soils makes their behavior different from that of a reconstituted material. In fact, most clays lose a proportion of their strength when remoulded. Various authors proposed anisotropic elastoplastic soil models allowing the yield surface to rotate with the stress history. These models have a “rotational hardening law" which relates the change of the inclination of the yield surface to the current soil state and to the increments of the plastic volumetric and/or shear strain, [Sekiguchi and Otha (1977)], [Hashiguchi and Chen (1998)], [Wheeller et al (2003)]… Other authors combine the plastic anisotropy with destructuration effects observed in soft sensitive soils by assuming that the size and /or the position of the center of the yield surface depends on the amount of the structural soil degradation. These models use an additional isotropic hardening law that relates the size and/or the position of the yield surface of the intact sample to that of the reconstituted one [Nova et al (2003)]. The previous models provide little or no flexibility when it comes to describe the change of the plastic modulus with the loading direction as they are unable to produce a smooth degradation of the stiffness, being single yield surface models. A way to improve this behavior is to introduce the “bounding surface plasticity” theory, initially developed by Dafalias [Dafalias and Herrmann 1986]. Unlike a single yield surface model, the bounding surface theory allows a smooth transition of stresses within and on the bounding surface. The mean feature of this concept is that the actual stress is mapped to the imaginary stress on the bounding surface. The distance between the real and imaginary stress, which is called the “ function distance ”, is used to specify the plastic modulus. This work presents a bounding surface plasticity model for natural and structured clays based on the critical state theory. A novel rotational hardening rule for clays is presented, and a hardening function distance is introduced to describe the evolution of the bounding surface. Validation of the model is provided by drained and undrained tests of Scottish and Finnish intact and reconstituted clays [Kastunnen 2008]. Finally, finite element simulations of a foundation considering the formulated constitutive law are presented. [less ▲]

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See detailCompetition between finite-size effects and dipole–dipole interactions in few-atom systems
Damanet, François ULg; Martin, John ULg

in Journal of Physics : B Atomic Molecular & Optical Physics (2016), 49

In this paper, we study the competition between finite-size effects (i.e. discernibility of particles) and dipole–dipole interactions in few-atom systems coupled to the electromagnetic field in vacuum. We ... [more ▼]

In this paper, we study the competition between finite-size effects (i.e. discernibility of particles) and dipole–dipole interactions in few-atom systems coupled to the electromagnetic field in vacuum. We consider two hallmarks of cooperative effects, superradiance and subradiance, and compute for each the rate of energy radiated by the atoms and the coherence of the atomic state during the time evolution. We adopt a statistical approach in order to extract the typical behaviour of the atomic dynamics and average over random atomic distributions in spherical containers with prescribed k0 R with k0 the radiation wavenumber and R the average interatomic distance. Our approach allows us to highlight the tradeoff between finite-size effects and dipole– dipole interactions in superradiance/subradiance. In particular, we show the existence of an optimal value of k0R for which the superradiant intensity and coherence pulses are the less affected by dephasing effects induced by dipole–dipole interactions and finite-size effects. [less ▲]

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